1.
Phys Rev Lett
; 111(16): 162002, 2013 Oct 18.
Article
in English
| MEDLINE
| ID: mdl-24182256
ABSTRACT
We calculate, for the first time using unquenched lattice QCD form factors, the standard model differential branching fractions dB/dq2(BâKâ(+)â(-)) for â=e, µ, τ and compare with experimental measurements by Belle, BABAR, CDF, and LHCb. We report on B(BâKâ(+)â(-)) in q2 bins used by experiment and predict B(BâKτ(+)τ(-))=(1.41±0.15)×10(-7). We also calculate the ratio of branching fractions R(e)(µ)=1.00029(69) and predict R(â)(τ)=1.176(40), for â=e, µ. Finally, we calculate the "flat term" in the angular distribution of the differential decay rate F(H)(e,µ,τ) in experimentally motivated q2 bins.